Amazon has been granted a patent that paves the way for it to potentially offer drone surveillance as a new business solution. The patent was filed back in 2015.The USPTO "Unmanned Aerial Vehicle Based Surveillance as a Service" patent describes how an unmanned aerial vehicle (UAV), or drone, can "perform a surveillance action at a property of an authorised party."The surveillance functions of the drone can be restricted through geo-fencing, a form of technology used in drones to define areas which are acceptable to fly over and those that are restricted, such as airports and military bases. The patent also describes how the drone could be used to generate images of a location both in - and outside - of a geo-fence, reported San Francisco's ZDNet.The patent states: "While gathering surveillance images, or after the surveillance images have been gathered, the geo-fence information may be used to obscure or remove image data referring to objects outside the geo-fence."The images could be stored or sent to another device and "surveillance alerts" can be issued for events of interest such as a break-in or fire.Surveillance as a service could, for example, be an option for consumers willing to 'hire' a UAV to keep an eye on their property, or a solution for businesses that need overnight facility monitoring.This month the retail giant announced a drone designed for commercial package delivery. Launched as part of the Prime Air programme, the UAV aims to deliver packages to customers in less than 30 minutes. However, the company's drone delivery aspirations have not yet materialised.